[name]Matilda[/name] nn [name]Millie[/name] could be cute!
I do love your children’s names! And wow, 9 (almost 10) must be a handful! Hehe.
Some other ideas in a similar style to your other names without repeating initials are:
A- [name]Alice[/name], [name]Anna[/name], [name]Annabel[/name], [name]Arabella[/name], [name]Ariana[/name], [name]Adele[/name], [name]Anastasia[/name], [name]Angelica[/name], [name]Agatha[/name], [name]Allegra[/name], [name]Adelaide[/name], [name]Agnes[/name], [name]Annika[/name], [name]Astrid[/name], [name]Amalia[/name], [name]Anwen[/name], [name]Ailsa[/name], [name]Ariella[/name], [name]Ariane[/name], [name]Anneliese[/name], [name]Althea[/name], [name]Avery[/name], [name]Adria[/name], [name]Amity[/name], [name]Amabel[/name], [name]Annora[/name],
B- [name]Beatrice[/name], [name]Beatrix[/name], [name]Bridget[/name], [name]Blythe[/name], [name]Blair[/name], [name]Bellamy[/name]
D- [name]Delilah[/name], [name]Diana[/name], [name]Dana[/name], [name]Dahlia[/name], [name]Daria[/name], [name]Dinah[/name], [name]Delaney[/name],
F- [name]Francesca[/name], [name]Freya[/name], [name]Fiona[/name], [name]Fia[/name], [name]Florence[/name], [name]Felicity[/name], [name]Florentina[/name]
H- [name]Harriet[/name], [name]Helena[/name], [name]Hazel[/name], [name]Heather[/name], [name]Helen[/name], [name]Holland[/name]
I- [name]Imogen[/name], [name]Iris[/name], [name]Ivy[/name], [name]India[/name], [name]Ingrid[/name], [name]Irina[/name], [name]Isaline[/name], [name]Isannah[/name]
K- [name]Kate[/name], [name]Katya[/name], [name]Katherine[/name], [name]Kara[/name]
M- [name]Martha[/name], [name]Mary[/name], [name]May[/name], [name]Mabel[/name], [name]Margot[/name], [name]Mara[/name], [name]Melina[/name], [name]Mirabelle[/name], [name]Mattea[/name]
N- [name]Natalia[/name], [name]Natalie[/name], [name]Nina[/name], [name]Nadia[/name], [name]Nora[/name], [name]Nola[/name], [name]Noelle[/name]
O- [name]Olive[/name], [name]Odette[/name], [name]Octavia[/name], [name]Oriana[/name]
P- [name]Phoebe[/name], [name]Poppy[/name], [name]Penelope[/name], [name]Pearl[/name], [name]Paloma[/name]
R- [name]Rhiannon[/name], [name]Rosa[/name], [name]Ruth[/name], [name]Rosemary[/name], [name]Romilly[/name], [name]Rosanna[/name], [name]Ramona[/name], [name]Rowena[/name], [name]Rosalyn[/name], [name]Rosalia[/name], [name]Rosalie[/name], [name]Rosamund[/name]
V- [name]Veronica[/name], [name]Valentina[/name], [name]Vivien[/name], [name]Viola[/name], [name]Vida[/name], [name]Viviana[/name]
W- [name]Willow[/name], [name]Willa[/name], [name]Whitney[/name], [name]Wren[/name]
I think also since you’re eldest child’s inital begins with a Z it could be a cute idea to have the youngest’s begin with an A so you’ve kind of gone full circle!
Best of luck 